class A {
    public int f(int x, int y) {
        return x + y;
    }
}

class B extends A {
    public int f(double x, int y) {
        return (int) x * y;
    }
}

public class E {
    public static void main(String args[]) {
        B b = new B();
        int m = b.f(3, 5);  //
        A a = b;
        int n = a.f(3, 5); //
        System.out.printf("%d:%d", m, n); //【代码】
    }
}
